Knowledge Test Class B #1
Class B Driving Test | Iowa 2025 #1 Page 4 of 7
Train for FREE online with our Iowa class B license test. The official exam test consists of several obligatory parts, with all of them checking your knowledge of different blocks of road rules. If you need to obtain a IA CDL class B permit in 2025, practice as much as possible. Free sample tests published on our website will help you check and improve your knowledge and boost your grades. Please bear in mind that CDL class B requirements may vary from state to state.
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22 . During a static leakage test, what is the maximum leakage rate that is safe for a double combination vehicle?
When performing a static leakage test on a double combination vehicle with air brakes, the leakage rate should be no more than 3 psi in one minute. If the air leaks from the air brake system at a quicker rate, the vehicle should not be driven because something likely needs to be repaired.
23 . When driving:
You should always use turn signals to warn others about your intentions.
It is important to communicate your intentions to others on the road. Make sure to signal before turning or changing lanes, even if no other vehicles are nearby.
24 . When transporting a load, you should inspect the cargo:
Cargo and its securement must be inspected every time you take a break during a trip. Be sure to inspect the cargo at least every 150 miles.
25 . A low air pressure warning signal should activate:
When tank pressure falls below 5 psi.
In an air brake system, a low air pressure warning signal must come on if air pressure in the tanks falls below 60 psi. This warning signal may come in the form of a light, a buzzer, or a wig wag.
26 . Which of the following is not a cause of hydraulic brake failure?
Most cases of hydraulic brake failure come from one of two causes. The brakes may fail due to a loss of hydraulic pressure or due to overuse on long hills, causing the brakes to fade.
27 . Operating a CMV with any measurable amount of alcohol in your system will result in an out-of-service order for:
One year.
If you are found to be driving with any detectable amount of alcohol in your system, but are still below the legal limit of 0.04 percent, you will put out-of-service for a period of 24 hours.
28 . Watching the road ahead of you:
Always watch for hazards on the road ahead. Doing this will allow you time to react to hazards before meeting them.
2025 Iowa | Frequently Asked Questions
A CDL Class A license in Iowa is defined as a commercial driver's license that permits the holder to operate any combination of vehicles with a Gross Vehicle Weight Rating (GVWR) of 26,001 pounds or more, provided the GVWR of the vehicle(s) being towed is in excess of 10,000 pounds. This includes tractor-trailers, truck and trailer combinations.
A Class A CDL license in Iowa allows the holder to operate various types of vehicles including tractor-trailers, truck and trailer combinations, tank vehicles, livestock carriers, and flatbeds. The license covers vehicles with a Gross Vehicle Weight Rating (GVWR) over 26,001 pounds and the towed vehicle is more than 10,000 pounds.
To obtain a Class A CDL license in Iowa, you must be at least 18 years old (21 for interstate driving), possess a valid non-commercial driver's license, and pass a vision test. You'll also need to pass written knowledge tests, a skills test, and a pre-trip vehicle inspection. For certain endorsements like hazardous materials, a background check is required.
In Iowa, you must be at least 18 years old to qualify for a Class A CDL license. However, please note that while you can obtain a CDL at 18, federal law requires drivers to be at least 21 years old to drive commercial vehicles across state lines or to transport hazardous materials.
Specific endorsements aren't required for a Class A CDL license in Iowa but they can enhance your license. Endorsements like "T" for double/triple trailers, "P" for passenger vehicles, or "H" for hazardous materials allow you to operate specific types of vehicles or carry certain types of cargo. Each endorsement requires passing additional tests.
The Class A CDL skills test in Iowa encompasses three main areas: pre-trip inspection, basic vehicle control, and on-road driving. The pre-trip inspection tests your ability to inspect your vehicle before driving. Basic vehicle control assesses your ability to control the vehicle. On-road driving tests your ability to drive the vehicle in various traffic situations, including turns, intersections, and highway driving.
Yes, Class A CDL license holders in Iowa may face limitations based on their medical qualifications, the type of vehicle they're allowed to operate, and the cargo they can transport. This could result in restrictions such as "No passengers", "Intrastate only", or "No air brake equipped". Also, drivers under 21 are limited to intrastate operation only.
In Iowa, the written Class A CDL test is primarily administered in English. However, some locations may offer the test in Spanish. It's important to note that even if the test is taken in Spanish, the Federal Motor Carrier Safety Administration requires all commercial drivers to read and speak English sufficiently to converse with the general public, understand highway traffic signs and signals, respond to official inquiries, and make entries on reports and records.
Yes, you can request accommodations for the Class A CDL written test in Iowa if you have a disability. The Iowa Department of Transportation is committed to providing reasonable accommodations in accordance with the Americans with Disabilities Act. You should contact your local DOT office in advance to discuss your needs and arrange for modifications or aids to assist you during the test.
Yes, if you don't pass the Class A CDL written test in Iowa, you can retake it. However, you must wait at least one day before retaking the test. Please note that there may be additional fees for each retest. It's advised to review your study materials thoroughly before attempting the test again to increase your chances of passing.